P.861 was recognized as having certain limitations in specific areas of application. It was replaced by P.862, which contains an improved objective speech quality assessment algorithm. P.861 included one diskette containing test vectors for implementation verification of the PSQM algorithm

Objective quality measurement of telephone-band (300-3400 Hz) speech codecs
P.861 was recognized as having certain limitations in specific areas of application. It was replaced by P.862, which contains an improved objective speech quality assessment algorithm. P.861 included one diskette containing test vectors for implementation verification of the PSQM algorithm